SAM I Exam I Material Flashcards
T/F: Dilated cardiomyopathy (DCM) is a common condition in large and giant breed dogs
True
Most common in Doberman Pinschers, Boxers, Cocker Spaniels, Irish Wolfhounds
T/F: Pulmonic stenosis responds well to balloon valvuloplasty
True
What do brick red mucous membranes indicate?
Erythrocytosis or Right-to-Left Shunt
List 3 differentials for hyperkinetic pulse:
Exercise, Anemia, PDA (shunt)
What is the appropriate treatment for Sinus Sick Syndrome?
Pacemaker
What type of medication is contraindicated to treat Tetralogy of Fallot?
Vasodilators
Vasodilators will exacerbate R-L shunting and hypoxia!
What is the most common clinical sign associated with Atrial Septal Defect?
None!
Most dogs with ASD are asymptomatic. Very severe cases may develop heart failure signs
__________ provides the definitive diagnosis for DCM
Echocardiography
- Left ventricular and left atrial enlargement with “flabby” ventricular walls.*
- **DCM is most commonly seen in Doberman Pinschers!***
T/F: PDAs are more common in females
True
With which cardiac disease is atrial fibrillation most associated?
Dilated Cardiomyopathy
However it also occurs in dogs with underlying heart disease
Diastolic murmurs indicate insufficiency where?
Aortic or pulmonary valve
T/F: Aortic Stenosis is more common in dogs than in cats and causes increased afterload, which results in left ventricular concentric hypertrophy
True
Left ventricular emptying is impaired because of high outflow resistance caused by a reduction in the valve orifice area when it opens. This high outflow resistance causes a large pressure gradient to occur across the aortic valve during ejection, such that the peak systolic pressure within the ventricle is greatly increased. This leads to an increase in ventricular afterload, a decrease in stroke volume, and an increase in end-systolic volume.
A wide P wave indicates:
left atrial enlargement
T/F: Signs of right heart failure eventually occur in patients with left-to-right shunting patent ductus arteriosus (PDA)
False
Blood is shunted through the PDA from the aorta to the pulmonary artery (left to right). This leads to volume overload of the left heart, which may result in _left-sided congestive heart failure_.
Right heart failure may occur with RIGHT-TO-LEFT shunting PDAs
Sinus bradycardia occurs when the ventricular rate is too slow. What are the reference values for dogs and cats?
Under 60-70 bpm in dogs
Under 100 bpm in cats
The majority of cases of dilated cardiomyopathy (DCM) in cats are due to:
taurine deficiency
Unlike in dogs, taurine is an essential amino acid in cats as they have a limited ability to synthesize taurine.
If the underlying cause can not be corrected, what is the only definitive treatment for a third-degree AV block?
Pacemaker
An R wave that is too tall indicates:
LV enlargement
T/F: Tall spiked T wave, prolonged PR interval, small P wave, and wide QRS are all indicative of hyperkalemia
False
Tall spiked T wave, small P wave, and wide QRS are all indicative of hyperkalemia. NOT prolonged PR interval
The location of the apical beat is the best place to hear:
mitral valve
In which breed is Boxer Cardiomyopathy most common?
…Boxers
T/F: A Holter monitor is useful for monitoring electrolyte disturbances
False
A Holter monitor is useful for monitoring arrhythmias
If an animal has cough, fatigue, dyspnea, and orthopnea at night or with any activity, what stage of left heart failure is the animal in?
Stage III
What are we looking at here?
Right Bundle Branch Block
T/F: Radiography is the best imaging modality for measuring heart size
False
Echocardiography is.
T/F: Endocardiosis is characterized by decreased contractility of the heart
False!
In patients with endocardiosis, there is thickening and contraction of the AV valve, resulting in valve incompetence. The heart compensates by increasing sympathetic tone, which increases contractility
What is the key prognostic factor for cats with hypertrophic cardiomyopathy (HCM)?
Left Atrial size
(over 20 mm carries a very poor prognosis)
Name a few things that can cause a low voltage QRS:
- obesity
- pleural effusion
- pericardial effusion
- hypothyroidism
- pneumothorax
- diffuse myocardial disease
T/F: A prolonged P-R interval is indicative of hyperkalemia
False
What are the three phases of dilated cardiomyopathy (DCM) in dogs?
Arrhythmogenic, Occult, Classic
What cardiac abnormalities are indicated by cyanotic mucous membranes?
R-to-L shunts, severe left heart failure
T/F: Supraventricular Premature Depolarizations (SPDs) have normal QRS complexes
True
T/F: Aspirin is indicated for treatment of aortic thromboembolism (ATE) in cats
True
The low dose of aspirin is thought to inhibit production of thromboxane, which is important in platelet aggregation and vasoconstriction, but not prostacyclin, which is an important vasodilator and inhibitor of platelet aggregation away from sites of blood vessel wall damage
What is the drug therapy of choice to treat VPDs in cases of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)?
Sotalol, or Mexiletine & Atenolol
**A recent report indicates omega-3 fatty acids (EPA and DHA) might decrease the number of VPDs**
At what age do dogs with occult DCM go on to develop classic DCM?
6-9 years
T/F: Warfarin is a safe and effective treatment for ATE in cats with HCM
False
Warfarin can cause fatal hemorrhage and is difficult to titrate properly.
T/F: The T wave can be positive, negative, or biphasic and still be considered normal
True
When is treatment of VPDs indicated?
- CO is reduced and there are clinical signs
- Patient has disease known to be associated with sudden death (Boxer cardiomyopathy, Dobermans with DCM, etc.)
- High heart rate, R-on-T, or if ectopic VPDs occur at high frequency (>30/min)
What’s going on here?
Ventricular Premature Depolarization (VPD)
T/F: ACE Inhibitors block myocardial remodeling induced by RAAS in CHF
True
ACE inhibitors slow the progression of heart failure, block remodeling and fibrosis due to Angiotensin II and aldosterone, enable up to 50% reduction in furosemide dosage, & prolong and improve quality of life
Which of the following is an indication of left ventricular enlargement?
- ↑ P wave
- ↑ Q wave
- ↑ R wave
- ↑ S wave
- ↑ T wave
↑ R wave
T/F: Ventricular premature depolarizations (VPDs) will have a wide, bizarre QRS complex
True
VPDs occur prematurely and the QRS complexes are usually wide and bizarre because they spread through the muscle rather than through the normal conducting pathways in the heart
T/F: Aortic Stenosis is more common in dogs than in cats and causes increased preload, which hastens the development of pulmonary edema
False
Aortic Stenosis is more common in dogs than in cats and causes increased afterload, which results in left ventricular concentric hypertrophy
T/F: In a canine patient with left ventricular enlargement you should note a wide (prolonged) QRS complex
True
You will see increased R wave voltage and prolonged QRS complex
Difficulty breathing while lying down is termed:
orthopnea
What is the best treatment for aortic stenosis?
β-blockers
Treatment for aortic stenosis is usually palliative, but β-blockers may increase diastolic function. Sotalol is the drug of choice.
T/F: Enalapril is effective in delaying the progression of myxomatous mitral valve degeneration in dogs
False
There is currently no therapy that will halt or delay the progression of myxomatous mitral valve degeneration in dogs
Radiographically, what is the most consistent feature associated with endocardiosis?
left atrial enlargement
What disease is most commonly responsible for coughing in an old dog?
Small Airway Disease
Coughing in an old dog is LEAST commonly due to myxomatous mitral valve disease that has progressed to heart failure
At what age do dogs with arrhythmogenic cardiomyopathy (ACM) go on to develop occult DCM?
3-6 years
Ventricular Septal Defect (VSD) causes a murmur that is loudest on which side of the animal?
Right
A systolic murmur loudest over the right sternal border is the norm for VSD
What is the drug of choice for treatment of ventricular premature depolarizations (VPDs) in the acute setting (R-on-T, high numbers of multiform VPDs)?
Lidocaine
T/F: Concentric hypertrophy is caused by pressure overload
True
Concentric hypertrophy occurs when there is increased systolic ventricular pressure (pressure overload)
What is the most common cause of pericardial effusion in dogs?
Neoplasia
~70% of cases are due to neoplasia. ~20% are idiopathic
T/F: Pimobendan is a vasodilator and a negative ionotrope
False
Pimobendan is a vasodilator and a positive ionotrope
T/F: Supraventricular Premature Depolarization (SPD) is associated with a prolonged QRS
False
T/F: Most cats don’t develop clinical signs as a result of hypertrophic cardiomyopathy (HCM)
True
That is true.
Identify the arrhythmia.
Atrial Flutter
Note the sawtooth pattern on the ECG. This pattern is due to rapid rotary depolarization of the atria
T/F: Aortic stenosis is not an inherited condition; the animal can be bred
No!
T/F: In a feline patient with left ventricular enlargement you should note a wide (prolonged) QRS complex
False
In cats, increased R wave voltage is the only indicator of left ventricular enlargement
Briefly describe the pathophysiology of Endocardiosis:
Mitral valve incompetence → regurgitation of blood to the atrium → left atrial enlargement → volume overload → eccentric hypertrophy
Mitral valve incompetence results in regurgitation of blood to the atrium in systole. As valve degeneration progresses, the regurgitation increases, resulting in left atrial enlargement that compresses the left main bronchus against the aorta. The volume overload of the left ventricle causes eccentric hypertrophy and may eventually result in heart failure with pulmonary congestion
Identify the arrhythmia.
Atrial fibrillation
Note the absence of P waves and the variable R-R intervals
T/F: If you give supplemental taurine to cats with DCM, you should see clinical and echocardiographic improvement after 2 weeks
Nope! Well, sort of…
If you give supplemental taurine to cats with DCM, you should see clinical improvement _after 2 weeks_ and echocardiographic improvement _at about 6 weeks_
Identify the arrhythmia. Note the absence of P waves, random R-R intervals, and normal QRS complexes
Atrial Fibrillation
- On physical, the heart sounds are chaotic (“like a 5-year-old playing the drums”)*
- If the animal has normal heart function and normal ventricular rates, they probably do not require treatment!*
How do ACE Inhibitors work in Heart Failure?
They block the body’s production of angiotensin II, thereby relaxing blood vessels and lowering blood pressure.
This decreases the amount of work the heart has to do.
What would you expect to see with the P wave in a patient with left atrial enlargement?
increased duration of P wave
Describe what you might see on radiographs in a case of Ventricular Septal Defect (VSD):
- Prominent pulmonary vessels (due to pulmonary overcirculation)
- Left heart enlargement (due to volume overload)
- Large VSDs and R-L shunts may lead to right heart enlargement
How would you confirm and grade aortic stenosis?
Doppler
In an animal with Ventricular Septal Defect (VSD), is the prognosis better with a loud murmur or a soft murmur?
Loud Murmur
T/F: Whole body cyanosis may be seen in patients with Tetralogy of Fallot
True
More R-L shunting will occur during exercise. Deoxygenated blood is then not pumped to the lungs but instead into the systemic circulation, leading to cyanosis and erythrocytosis
T/F: In dogs with dilated cardiomyopathy (DCM), atrial fibrillation is best controlled with propranolol or diltiazem. If these are ineffective alone then digoxin should be added to the treatment
False.
In dogs with DCM, atrial fibrillation is best controlled with β-blockers such as atenolol or metoprolol.
Diltiazam is effective in controlling heart rate, but have the same cardioprotection of β-blockers. Digoxin is not very effective in controlling lone atrial fibrillation
T/F: The key prognostic factor for cats with hypertrophic cardiomyopathy (HCM) is the size of the left ventricle
False
The key prognostic factor for cats with hypertrophic cardiomyopathy (HCM) is the size of the left atrium (over 20 mm carries a poor prognosis)
T/F: Pericardial effusion usually results in right heart failure
True
If an animal that has runs (at > 160-180 bpm) of more than 3 VPDs in sequence, this is called:
Ventricular Tachycardia (VT)
Specifically what diet is not recommended for dogs with DCM?
Lamb & Rice Diets
p 54 of Dr. Kelly’s notes
Which portion of the heart is most effected in the case of Endocardial Fibroelastosis?
Left Ventricle
- This is seen primarily in Burmese and Siamese cats. There is fibrosis of the ventricular endocardium leading to stiffening of the walls of the left ventricle and eventual dilation and failure.*
- There is no treatment and prognosis is very poor.*
What’s this nonsense?
Sinus Arrest
- Note the long pause, absence of P wave, and normal QRS complex (with junctional escape beat)*
- **with ventricular escape beat QRS will be wide and bizarre***
A larger PDA will tend to shift:
Right-to-Left
With very large PDAs, overcirculatoin of the lungs may lead to increased pulmonary vascular resistance, such that flow in the PDA shifts from L-R to R-L usually around 6-8 weeks of age
T/F: Diuretics are effective in treating cardiac tamponade as a result of pericardial effusion
False!!
Diuretics are contraindicated in this case as they decrease blood volume and cause further collapse of the cardiac chambers
Between supraventricular premature depolzarization (SPD) and ventricular premature depolarization (VPD), which one has a QRS complex that looks normal?
Supraventricular Premature Depolarization (SPD)
Ventricular premature depolarization (VPD) will have a wide, bizarre QRS complex
What is the treatment for cardiac tamponade?
Pericardiocentesis
Identify the arrhythmia.
Ventricular Fibrillation
This is life-threatening and usually terminal. Treatment is usually futile in animals with severe systemic or heart disease. Treatment of choice is electrical cardioversion - external countershock/defibrillation with DC current
A cat presents with painful rear-limb lameness. You notice a murmur on physical exam and decide to take radiographs. You note pronounced left atrial and left ventricular enlargement that give a “valentine-shaped” heart in the dorso-ventral view.
What is your top differential diagnosis?
Hypertrophic Cardiomyopathy (HCM)
Identify the arrhythmia.
Sinus Arrhythmia
There is a normal P wave for every normal QRS complex, but the R-R intervals vary
T/F: Biatrial enlargement and biventricular enlargement can be diagnosed on ECGs
False
Biventricular enlargement can not be diagnosed on ECG
What is the recommended treatment for dogs with moderate to severe pulmonic stenosis?
Balloon Valvuloplasty
Abnormally high heart rate with normal P and QRS-T complexes describes what type of arrhythmia?
Sinus tachycardia
It is usually due to increased sympathetic tone, but can also be due to hyperthyroidism, drugs, etc.
Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is a familial disease of what dog breed?
Boxers
Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is also known as Boxer Cardiomyopathy
T/F: ACE Inhibitors are very effective for emergency therapy of animals with various forms of heart failure
False
ACE Inhibitors are very effective for _chronic maintenance therapy_ of animals with various forms of heart failure. ACE Inhibitors:
- slow progression of heart failure
- blunten remodeling and fibrosis due to ATII and aldosterone
- enable reduction in furosemide dosage
- prolong and improve quality of life
The most common organism associated with endocarditis is:
Bartonella spp.
T/F: Hypertrophic cardiomyopathy in cats is characterized by left ventricular concentric hypertrophy
True
Identify the three types of DCM in order of progression:
Arrhythmogenic, Occult, Classic
What are the two most common causes of pericardial effusion in cats?
FIP and Lymphoma
In which dog breeds do we typically see Patent Ductus Arteriosus (PDA)?
Toy & Miniature Poodles and German Shepherds
If mild-to-moderate heart failure does occur in a dog with myxomatous AV valves, what is the recommended therapy?
Furosemide & ACE inhibitors
Furosemide helps to control the pulmonary edema. ACE inhibitors are used to vasodilate and to help control RAAS activation
Is endocardiosis more common in small or large breed dogs?
What is the most common breed?
Small
Cavalier King Charles Spaniel
If you hear a continuous murmur and loud “water hammer” pulses, what should be your top differential?
L-R shunting PDA
T/F: Eccentric hypertrophy is caused by pressure overload
Nope
Eccentric hypertrophy is caused by _volume overload_
Concentric hypertrophy is caused by pressure overload
T/F: Myxomatous AV degeneration occurs primarily in large breed dogs
False
It can occur in large breed dogs, but myxomatous AV degeneration occurs mainly in small to medium breed dogs.
An older male cat presents with dyspnea. You note retinal degeneration and a large cardiac sillhouette on radiographs. The cat’s owner cooks the cat’s meals for him.
What is your top differential?
Dilated Cardiomyopathy (DCM)
With DCM, dyspnea is usually present. The retinal degeneration is suggestive of taurine deficiency (backed up by the fact that his owner cooks for him). The cardiac sillhouette on radiographs is to due to pleural effusion
Which type of murmur is more common: systolic or diastolic?
Systolic
Systolic murmurs are more common than diastolic murmurs
Identify the arrhythmia.
Atrial Flutter
Note the sawtooth pattern on the ECG. This pattern is due to rapid rotary depolarization of the atria
